Simulation And Measurement Of UHF RFID Tag Antenna

Radio frequency identification technology (RFID), which utilizes radio frequency signals to achieve non-contact automatic identification emerged since the end of the 20th century,is receiving wide attentions and getting applied rapidly around the world because that the UHF RFID harbors the specialities such as longer working distance, faster recognition speed and depth and so on. With the expansion of the UHF RFED application requirements in recent years, its working condition is becoming more and more roger, the performance of RFID tags needs to be elevated continuously to meet different application requirements in various working conditions.RFID tag is the data medium of a RFID system, while the tag antenna affects the performance of the whole system as the communication bridge between the RFID tag and the RFID reader and plays an important role. The UHF RFID is put into application widely nowadays, especially the passive UHF RFID system. The performance of tag antenna dominantly affects the identification performance of the RFID tag, so research on RFID tag aerial has academic meaning and application value.This paper focuses on the electronic tag of passive UHF RFID. The basic knowledge of RFID including the its composition structure and working principles is present firstly. Then the theoretical basis and common performance parameters of the tag antenna is described. Several measure methods of important parameters is also introduced. At last, a radiation efficiency acquiring method based on measuring the three basic parameters of the passsive dipole tag antenna, namely the directivity, realized gain and power transmission coefficient, is proposed in this paper. The simulation is established and the results verify the rationality and feasibility of the proposed method. The information acquired from the measurement can be used to calculate the material structural damage of the tag antenna as well as to improve and optimize the antenna’s performance. The proposed method has a promising potential in practical application environment and measurement of different types of tag antenna used in RFID system.